In conventional dispensing devices used for automatic analyzers for analyzing blood, etc., liquid such as sterile water is used as pressure-transmitting fluid inside a syringe being used for the suction/discharge of liquid. Since liquid has the property of hardly changing its volume in spite of changes in the pressure and/or temperature, the distance between the syringe and a nozzle for sucking/discharging liquid has little effect on the dispensing accuracy, irrespective of length. Thus, such dispensing devices are configured such that the syringe is generally set at a position apart from the nozzle of the dispensing device and connected to the nozzle with a long tube. However, facilities for supplying the liquid to the device and dumping liquid waste are necessary.
Meanwhile, the present inventors are developing an analyzer for genetic testing in these years and are examining the use of air for the pressure-transmitting fluid inside the syringe being used for the suction/discharge of liquid. When liquid is used as the pressure-transmitting fluid in a genetic testing device, the problem with contamination occurs since the liquid moves inside the nozzle used for the dispensing. Reduction of the effect of the contamination is especially required of genetic testing devices compared with other automatic analyzers for analyzing blood, etc.
However, in the case where air is used as the pressure-transmitting fluid, the change in the volume of the air caused by the change in the pressure/temperature is greater than that of liquid, and thus the distance between the syringe and a suction tip has to be reduced for improving the dispensing accuracy.
A known inspection device is contrived to reduce the distance between the syringe and the suction tip by placing the syringe inside the dispensing device (see FIG. 4 of Patent Literature 1, for example).